The ultimate beginner's guide to PC FANS

[oldone]

OO,

My dresser is not going well. I might have to use air from another room or reduce/change the lighting...

So right now I have one kick-ass, loud delta fan up top by the light bases as the exhaust. I have two times this size for passive intake on bottom. The fan is blowing like crazy on full-speed, but the temps are still about 8 degress hotter in the box than outside (room 73, box 81). This is without any scrubber and light traps. With scrubber and traps, it's going to get too hot-especially during summer. I think the problem is the hot air is being pushed out, but then sucked right back in since the dresser is only 29 inches high and all ports are on back.

I was trying for stealth, but I don' think I can do it. This fan is loud and I will need light traps. Considering cutting holes in wall next to dresser to either exhuast into or suck from.

Meanwhile my PC is fine in same room. Two 80mm, 28db fans sucking in air in front and one blowing out back (no scrubber though). 136 watts of spirals running only 3 degress hotter than room.

I can't help but think these 55W PLLs are just running too hot, or 4 in this space is too many. I have seen ah supply that you got yours from - proper reflectors/spacing might help somewhat, but I might try spirals to see how much heat they throw off. I still don't get how PLLs can be so hot, when I thought their best feature was their coolness.

O well, I'm going to keep experimenting and at some point start my own thread--I don't want to keep asking you questions on others' threads. I think I have learned mostly what I need to know, now it's just a matter of finding what works for me.

Yes when cranked the Deltas will be loud. You cant move air under pressure without making noise. I generally run mine around 50% speed and they are much quieter.

Are your PLL ballasts outside the chamber? That is one of the advantages over spiral cfls...remote ballasts. Something you may also consider is installing a sheet of glass under your lights. This wont let the hot air mix in the cab. I think Anti does it this way. I made provision for one but have not needed it.

Think of PLLs as spirals straightened out. The glass component will produce about the same amount of heat.

Your own thread is a good idea...be sure to let us know.
OO

 

[MeLikesPCs]

I'm back again with yet another question, but it belongs in this thread OK, so I got a fan controller, but the wires are not colored. How do I hook thiese up, trial and error? I see no labeling/color/difference between the 3 wires for each fan. I'm going to use the power adapter and not the molex. Thank you.

 

[oldone]

I'm back again with yet another question, but it belongs in this thread OK, so I got a fan controller, but the wires are not colored. How do I hook thiese up, trial and error? I see no labeling/color/difference between the 3 wires for each fan. I'm going to use the power adapter and not the molex. Thank you.

What about the manufacturer's web site? Maybe it has a wiring diagram...

 

[ganjasuiteseat]

hey i was woundering has anybody used cyclone blowers?peace and a peaceful harvest

 

[ScrubNinja]

hey i was woundering has anybody used cyclone blowers?peace and a peaceful harvest

You mean like this? I did buy a cheap one but never used it. They all seemed a bit lacking in specs when I looked. But I guess there could be a situation where they could be good.

Happy micro growing, micro dudes.

 

[kjz71521]

i started out with the pc fan but needed a lil more push to get threw the carbon.. they are good if you know which are the right ones to get.

 

[Aerohead]

Hey Scrub, been away for a while, good to see you are still here posting away. You have anything growin on at the moment?

 

[ScrubNinja]

Hi Aero!! I try to pop in when I can I sure do have a lil sumtin' sumtin' in the back yard! You're all welcome to visit my outdoor thread in the sig.



Those are all a purple kush I just pulled.

Hey so anyway, I went back a bit and here are some replies. Also, I see a few names that contacted me while my life was in a bit of a flux so, sorry I couldn't help/reply. You're in good hands here anyway

BillRose:

Re plugging the power adaptor into a dimmer switch - I'm pretty sure this is a bad idea, friend. A fan is just a simple motor and it can handle variations in the power supply, but the adaptor has like, circuitry and stuff inside. I'm not an electrician but I would liken the adaptor to plugging a CD player or computer into the dimmer switch. (not something I would try) Out of curiosity, is that setup still functioning ok?

phrike:

Hey thanks for the heads up on the voltage stuff. I'll try to edit that into the first post. Also the power adjustment on the PSU tip was cool! I had no idea that existed.

Yeah it would be straightforward enough to make a functioning PC as a grow cab I reckon. My thoughts, which I probably mentioned somewhere in the mess, are to pull apart a cheap netbook like the Asus EEE I'm typing on now. It's the 701 and they're very cheap. Happens to be my fav computer! I would essentially remove the screen and attach the keyboard part flat against the wall towards the rear of the PC so the monitor output, two USB slots, and the SD card slot would be like, somewhere vaguely in the right general area to access, haha.

On the other (left) side is just another usb slot, and the network/ethernet/whatever-it-is socket. I'd guess the network thing could be extended somehow? Otherwise it has wireless. Then, the only other issue I can think of is the power switch which wouldn't be hard to extend. There is a HUGE community of EEE modders and many pics of the internals etc, I think it's eeeuser.com. My unit is 225mm x 165mm and probably about 35mm at it's thickest. With your experience, you would do such a nice job of that I'm sure.

Strangely:

Thank you for not electrocuting yourself on my thread

Kalimaa:

Re "sugarcubes" - not sure what they are, apart from Bjork's old band, things horses like, and stuff to put acid on

OldOne:

Re "Delta fans are fantastic (no pun intended)." This had me giggling for WAY too long. Thanks for sticking around and good to hear the setup is going strong.

Sandnut:

Thanks a lot brother I guess the people who see it see it!

MeLikesPCs:

"How do I hook thiese up, trial and error?" - in lieu of a better answer - yes.

kjz71521:

Agreed!

 

[medicaluser2]

thanks scrub!

thanks scrub!

scrub, thank you for sharing all of your knowledge on this subject! i have a question about fan controllers and im wondering if anyone here had any insight.

there is a 4 fan controller for a pc that fits in a 5 " bay and has little knobs to control each of 4fans separately. (long time lurker first post and it wont let me post the link. but its on ebay "4fan controller ")

http://cgi.ebay.com/3-5-Bay-Panel-L...602?pt=LH_DefaultDomain_0&hash=item3efeea944a

EDIT. link added



i see it is powered by a 4pin molex adapter c0nnected to a single pc power supply channel (12v) so would each fan being controlled by this have to share the same 12v? so with 4fans attached you run 3v to each at max fan setting, is that right or can each fan on a controller consume the full 12v? ive got a delta 120 cfm that i want to run at about 6v but i have other fans too and im wondering if anyone can set me straight on how the voltage works with these things or if anyone has used these before with good success?

 

[Rouge]

Well medicaluser2, It already done for you. Each of the 4 outputs has 2 wires: a red one and a black one, which is 12V variable and a return, respectively, each. With 30W max, only 2.5 amps is available at 12 V; ie, if all the fans are at 12 volts only 2.5 amps is available for all of them, or 2.5/4 = 0.625 amps each. If you are using a fan that requires about 2.5 amps , you can use only one of the 4 outputs.

 

[Rouge]

If one or all the outputs are at 6V, then 30W/6V = 5 amps. So 5 amps must be shared by one or all 4 outputs, which is 5/4
= 1.25 amps each. So you can run 1 fan at 6v, 5 amps.....2 fans at 6V, 2.5 amps......... 3 fans at 6V, 1.67 amps....... OR...... 4 fans at 6V, 1.25 amps each. This is what the speed controller is supplying you with. Since you are going to vary the voltage, mmmm? I'm gonna have to think about that one.........Where's the fu@#$#ing joint at?

 

[Rouge]

I have made a few assumptions here. Namely that the max power of the speed controller is 30W, not 30W per channel, and that it's outputs are short circuit protected. Also one should not use more than 80% of the max power.

So the 30W now becomes 24W and now we have to redo our caculations (Sorry,not now...... it's just arithmetic).

Varying the voltage: Assume we have 2 fans. One requires 12V, 0.3A, the other requires 12V, 2.45A. 12V*0.3A=3.6W. 30W-3.6W=26.4W available for the 2nd fan. The 2nd fan requires 12V*2.45A=29.4W. This exceeds what we have left which is 26.4W. So 26.4W/12V= 2.2A. Maybe the 2nd fan will not spin or not spin fast enuff since it requires 2.45A for nominal speed and we have only 2.2A left.

So we can vary the voltage from 6V to 10.8V. At 6V, the current will be 26.4W/6V=4.4A. So while varying the voltage from 6V to 10.8V, the current will vary from 4.4A to 2.2A. Between 10.8V and 12 V, you are stuck with 2.2A.

Just make sure that your fan(s) Amps does not exceed (80% of) the speed controller amps.

 

[ScrubNinja]

Hi Medi! Thanks Rouge for trying to help! I think the main problem here is that this is a dodgy cheapo ebay fan controller. With any decent one, they'll give you a maximum watts or amps per channel, whereas that one just gives an overall limit (30w). So I dunno really, but I can tell you that 30w = 2.5amps, which is a decent amount. Maybe hit the ebay guy up and ask the limit per channel if you want to be sure, but my advice would be to get a name brand style. If this thing fails, your plants may well be dead, or worse, so it's worth putting a few coins into imo Good luck!

 

[majortom9]

Nice work here ScrubNinja. I have a small box on the drawing board and need to jack up the static pressure of my PC fan and im thinking about just stacking 2 together to get enough umph to pull through 1" of carbon. I read here that they need a spacer between them to make it work properly and was wondering how thick of a spacer.If you could put me on the right track, a link, or maby you or someone else here knows the answer I would appreciate it, Ive looked but cant seem to find anything on it. Peace

 

[majortom9]

Well, I guess I couldn't see the forest for the trees, it was right there on the first page lol. So about the thickness of the fan shroud is what I need ? If not please hollar at me with a better solution. Peace

 

[Rouge]

STAY AWAY from the speed controller medicaluser refers to. Stay far away because it will burn your house down!
First off, that 30W max is fiction, more of typo error than reality. It's closer to 3W. I saw one in action and it was smoking at 12V and <1A. Scared the crap out of me. This controller controls a fan's speed by keeping the voltage constant (12V) and varying the current and it is NOT short circuit protected. That means it will burn rather than shut down if you ask for more current than it can supply. There is no literature/pamphlet/user-guide nor any maker info on the device. What's up with these folks from Hong Kong selling crap like this?

 

[smokeyjedi]

Hello guys.

1st post but iv been lurkin forever, need some expert advice on PC fans.

Iv been growing indoors since the OG days. My last set up involved a 400 HPS and can fan in a cab.

My situation has now changed and I need to downgrade to a 250 and I need total stealth so I cant use the can fan anymore.

Way back In the day when I had my first box a used 2 80mm pc fans to vent a 250 HPS cool tube and I 120mm attached to a scrubber to vent the cab, I would like to make a set up similar to this.

I saw this link and will be using a few ideas from that. https://www.icmag.com/ic/showthread.php?t=31172

Not sure if I will have separate veg area yet as I have switcable hps/mh digi ballast and I only grow from seed. I would like one if I can fit it I but its not a necessity, Sound levels are more important.

I have a sun system 2 air-cooled hood with 150mm outlets. Basically I want to cool this hood with 120mm PC fans, will these be any good? http://www.aria.co.uk/Products/Components/Fans%2C+Heatsinks%2C+Coolers/Case+Fans/120mm+Case+Fans/120mm+Silverstone+SST-AP121+Air+Penetrator%2C+1500rpm+%2C+FDB+-Breakthrough+in+Air+Channeling+Technology?productId=41333

The specs says its only 35.36CFM and 1.71mmH2O but if you watch the video in the link it seems to push a lot of air, Do you think this would be suitable for venting the hood? I was panning on using one to push one to pull but if I could get away with using one that would be better.

For the scrubber ( thinking of using a 125mm pro rhino carbon filter) I was thinking of this http://www.yoyotech.co.uk/item-detail.php?products_id=4368721 Again would you recommend one or two to get the desired effect?

The new cab will be In a bedroom, Normally only I will be in the room but on a rare occasion others may be in there as well so noise is a major concern.

Iv had a bit of practise trying to make my can fan quiet, built a mdf surround long lengths of ducting etc so I’m confident I could built a stealth extraction system but the reason I need your advice is that if I need to power down the fans to make the quiet enough do I need more of them?

I need to buy from a U.K store so if any of you would be kind enough to browse the links provided and see if there is anything better suited fro my plans?

Any advice is much appreciated


Thanks

 

[HIGHdration]

I'm making a box to grow in, and need some help picking a right fan for the job. Does anyone have any recommendations.

Box plans
https://www.icmag.com/ic/showthread.php?t=202258

 

[Voidling]

@smokeyjedi If you are venting the light and it does not need to be scrubbed then I would be looking for higher cfm and not worrying much about the pressure.

The other fan listed would definitely need two, and I'm not sure if that's enough pressure. I don't think the pressures add on top of each other and make it that simple but I'm not positive. It's been way too long since my fluid dynamics class.

 

[CARE giver]

I found a super strong fan with adjustable controller.

Airflow-Max. 72.91CFM
Static Pressure -Max. 13.78mmH2O

http://www.silverstonetek.com/products/p_spec.php?pno=fm81&area=usa

I have a question also though. My grow area is only going to be 12(l) x 7(w) x 15(h). Will this type of fan get rid of all smell(with a diy carbon scrubber of course)? I will be using some of my Apollo 11 clones also which aren't too smelly to begin with.